Anthocyanins: optimisation of extraction from Cabernet Sauvignon grapes, microcapsulation and stability in soft drink

The aim of this study was to establish the optimum conditions for the extraction of anthocyanins from Cabernet Sauvignon (Vitis vinifera L.) grapes using the response surface methodology and to evaluate the stability of these anthocyanins encapsulated with different carrier agents in an isotonic soft drink system under different light and temperature conditions. The extraction process was optimised with the response surface methodology to obtain the highest anthocyanin concentration (40 mL of ethanol:1.5 N HCL (85:15) as solvent, extraction time 29.4 h at pH 2.4). The degradation of the anthocyanins followed first-order kinetics in the situations evaluated. Maltodextrin, maltodextrin/γ-cyclodextrin and maltodextrin/arabic gum were tested as carrier agents and the combination of maltodextrin/arabic gum presented the longest half-life time and lowest degradation constant for all the conditions evaluated. The formation of microcapsules was observed through scanning electron microscopy.